Version control:

• Version control is a system that records changes to a file or set of files over time so that you can recall specific versions later.
• History of all changes (who, what, when).
• Helps to avoid mistakes (working on the wrong version, deleting, …).
• Merging changes of multiple collaborators in one file.

• Git is a essentially a programm on your computer, you have to communicate with it.
• Github (or gitlab) is a Git repository hosting service.

• A lot! Which is why I can only mention part of its functionality here.
• Working on one product in (large) teams.
• Working on things that can break.
• git can only integrate and show changes in text files.
• binary files (images, etc.) can be tracked and uploaded but changes cannot be shown.

• Git does not have a user interface.
• You can either use the terminal, or install an additional interface.
• Github has its own GUI. Some people like it.
• We will use Rstudio as user interface.

Tools ➤ Global Options ➤ Git/SVN.

Make sure the first box is ticked and the “git.exe” (Windows) is included in the first box.

• Open the Terminal in R Studio.
• Set an email address and user name for git.

• Open the Terminal in R Studio.
• Set an email address and user name for git.

git config --global user.email "myemail@email.com"
git config --global user.name "My commit name"

File ➤ New Project ➤ Version Control ➤ Git

• You will have to type in you user name and password for github.
• Initializes a local git repository with an R project (opening a clean R Studio session when opening).
• You can see the README file from github.
• Adds a .gitignore file.

• Specifies intentionally untracked files to ignore.
• Each line in a gitignore file specifies a pattern.
• R Studio pre-specifies some useful patterns.
• For R Markdown: Cache files! .tiff, .eps, .rdb, .rdx

• Tell other people (and yourself in a year) why your project is useful, what they can do with your project, and how they can use it.
• On github default README files are Markdown files!

git add .gitignore myfirstrepo.Rproj

• git can do autocomplete for file names!
• Note that many user interfaces combine git add and git commit (next step).

git add .gitignore myfirstrepo.Rproj
git commit -am "My first commit"

Commits always have a commit message.

git add .gitignore myfirstrepo.Rproj
git commit -am "My first commit"
git push

Congrats! You have done it! Now local and remote repositories are up to date!

Before you start working on the project the next time:

git pull

Pull, work some more, repeat.

git diff

First things first: You cannot break things.

Read the output!

• Resolve the conflict (Choose which changes to keep).
• Commit, and Push.

• The master branch is deployable: It contains the final product code.
• This is not where people work.
• Instead you use branches for development and then merge the code into the master branch once you are done.

I don’t really have time to get into this

• Here is the best tutorial I could find on branches: https://thenewstack.io/dont-mess-with-the-master-working-with-branches-in-git-and-github/.
• For working in a professional environment: A tutorial on pull requests: https://www.atlassian.com/git/tutorials/making-a-pull-request

• Add, commit, push, pull.
• Use it!
• git documentation and error tracking are great!

• Let’s make breakout rooms
• Then complete the in-class assignment.

Additional info (in the material folder):

Vuorre, M., & Curley, J. P. (2018). Curating Research Assets: A Tutorial on the Git Version Control System. Advances in Methods and Practices in Psychological Science, 1(2), 219–236.